Fields of Summer

Whenever a player casts a spell, that player may gain 2 life.
Whenever chaos ensues, you may gain 10 life.

Undercity Reaches

Whenever a creature deals combat damage to a player, its controller may draw a card.
Whenever chaos ensues, you have no maximum hand size for the rest of the game.

Quicksilver Sea

When you planeswalk to Quicksilver Sea and at the beginning of your upkeep, scry 4. (Look at the top four cards of your library, then put any number of them on the bottom and the rest on top in any order.)
Whenever chaos ensues, reveal the top card of your library. You may play it without paying its mana cost.

Goldmeadow

Whenever a land enters, that land's controller creates three 0/1 white Goat creature tokens.
Whenever chaos ensues, create a 0/1 white Goat creature token.

Planewide Disaster

When you encounter Planewide Disaster, destroy all creatures. (Then planeswalk away from this phenomenon.)

Talon Gates

Any time you could cast a sorcery, you may exile a nonland card from your hand with X time counters on it, where X is its mana value. If the exiled card doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, the player may cast it without paying its mana cost. If it's a creature, it has haste.)
Whenever chaos ensues, remove two time counters from each suspended card you own.

Nephalia

At the beginning of your end step, mill seven cards. Then return a card at random from your graveyard to your hand.
Whenever chaos ensues, return target card from your graveyard to your hand.

Time Distortion

When you encounter Time Distortion, reverse the game's turn order. (For example, if play had proceeded clockwise around the table, it now goes counterclockwise. Then planeswalk away from this phenomenon.)

Aretopolis

When you planeswalk to Aretopolis and at the beginning of your upkeep, put a scroll counter on Aretopolis, then you gain life equal to the number of scroll counters on it.
When Aretopolis has ten or more scroll counters on it, planeswalk.
Whenever chaos ensues, put a scroll counter on Aretopolis, then draw cards equal to the number of scroll counters on it.

Academy at Tolaria West

At the beginning of your end step, if you have no cards in hand, draw seven cards.
Whenever chaos ensues, discard your hand.

Eloren Wilds

Whenever a player taps a permanent for mana, that player adds one mana of any type that permanent produced.
Whenever chaos ensues, target player can't cast spells until a player planeswalks.

The Hippodrome

All creatures get -5/-0.
Whenever chaos ensues, you may destroy target creature if its power is 0 or less.